Hydraulic machine



May 18, 1954 E. w. woYD'r HYDRAULIC MACHINE 3 Sheets-Sheet l Filed Dec. 15, 1949 NQmNL INVENTOR .E IK /yor /ATTORNEYS 3 Sheets-Sheet 3 Filed Dec. 15. 1949` QNN wNN

INVENTOR E. Woyr ATTORNEYJ Patented May 18, 1954 UNITED STATES PATENT CFFICE Claims priority, application Germany' July 25, 1949 14 Claims.

The invention relates tohydraulic pumps and motors with cylinders radially arranged in a cy1- inder block in which the plungers or pistons are moved by eccentric members. In order to free the plungers in such machines of turning moments which are transmitted from the cylinder block on the eccentric member and Vice versa, it is known to provide between the plunger and eccentric member a plate freely adjustable and to ilx the position of the cylinder block to the eccentric member by couplings. In addition rollers between the plate and eccentric member helpto prevent the transmission of lateral forces on the plungers. However, it was found that the very small swinging motions which the plate makes about the pin which connects it to the plunger, and which are unavoidable owing to the elasticity of the material, unfailingly` cause friction oxidation. The arrangement of a single roller in the plunger or piston does not permit very high hydraulic pressuresand results in a substantially larger structure. This is also the case when special pots are placed over the cylinders in order to take up the track pressures by the lateral forces. A thickening of the piston end to a crosshead for the purpose of taking up the track pressures does not lead to the goal. Such crosshead if the plungers or pistons had anges inserted therein would have to be inserted with the same little play, however, with a larger diameter. This is first practically impossible and, second, would only result in excessive wear of the hanged-in crosshead instead of the piston.

'I'he invention utilizes between each plunger or piston and coordinated swinging member a yielding member and accomplishes the freedom of the plungers from tangential forces or turning moments, respectively, by the following construction:

Cylinders radially arranged in a cylinder block; pistons slidable in the cylinders; at least one eccentric member `cooperating with the pistons; between each piston and the eccentric member a member swingable about an axis parallel to the machine axis; between each piston and its swingable member a second member yielding transversely of the turning axis in such` a manner that turning moments. from the eccentric member through the yielding member owingto giving way of the yielding member are transmitted to the cylinder block andguideways or tracks embodied with the cylinder block and.through which all lateral forces arev transmitted which originate by the `action of the eccentric member `on -theswingable member.

When the swinging axis of the swinging member coincides with the axis of the yielding member and the swinging member by the eccentric member pressure is far enough advanced so that its lateral rollers press on'the guide track of the cylinder block, the yielding member rolls off the lower surface ci` the piston so that no lateral forces can act on the piston. For example, it can be ensured that forces acting in the direction of the plunger axis, or on both sides, in such a manner that the resulting force coincides with the plunger axis or approximates closely to the plunger axis. Hence' forces acting in the direction of the plunger axis but transmitted beside the plunger axis to the plunger would produce a moment tending to incline the plunger, so that at the end of the plunger a force would occur in a lateral direction, and at another point a force in an opposite direction.

The inventionhas importance in like manner for pumps and motors with a rotary cylinder star, as well as for designs in which the cylinders are stationary. It is especially of importance for engines with lapped plungers, in which the plungers travel within the cylinders without piston rings or the like, since such plungers wear rapidly and become leaky when lateral forces occur.

It is preferable to shape the yielding member as a cradle which is swingable at least in one plane, which is perpendicular to the rotation axis of the machine.

Moreover the invention makes it possible to create a machine occupying but little space. This purpose serves the fact that the yielding memu bers react by rollers against the guide tracks. For it a hydraulic machine of the present kind works with a reduced stroke, the paths of the pistons are very short. If then the yielding members with sliding means reacted upon the guide tracks, the danger or excessive wear on the guide tracks would exist unless the sliding means were of great length and in consequence take only a low specific load. Long sliding means have a heavy weight. In contrast thereto, the invention further aims to keep the weight of all movable parts 10W.

The invention has the further object of constructing a liquid pump or motor of the kind described with revolving cylinders in such a manner that the centrifugal forces of the pistons are taken up in a corresponding manner without exerting lateral components and that the friction losses of the pump or motor are kept low.

Further means for attaining. the named aims and further objects of the invention and the means for their realization are apparent from the following description of two embodiments and from the claims.

While both embodiments of the invention described hereinafter illustrate the eccentric mem ber in the center of the cylinder block and the cylinders outwardly thereof, it is to be pointed out that the reverse arrangement is possible. In the rst embodiment the centrifugal forces of the pistons are taken up by rings which are rigidly connected with two opposing plungers or pistons, while in the second embodiment the centrlfugal forces of the plungers or pistons are taken up by freely rotating rings. Such freely rotating rings are known by themselves. Y

The invention is not limited to the described and illustrated embodiment, but relates to all similar embodiments in which the same or similar effect is attained by the means of the invention.

The accompanying drawings illustrate by Way of example two embodiments of the invention, in

which: Y

Figure 1 is a vertical sectional view through a pump constituting a irst embodiment of the invention taken along lines I-I of Figure 4,

Figure 2 is a sectional View taken along lines 2 2 of Figure l,

Figure 3 is a sectional view taken along lines 3--3 of Figure l,

Figure 4 is a sectional view taken along lines 4--4 of Figure l,

Figure 5 is a sectional view taken along lines 5-5 of Figure l,

Figure 6 is a View similar to Figure l of a sec ond embodiment of the invention and taken along lines SI of Figure '7,

Figure 7 is a sectional View taken along lines 'l-'I of Figure 6,

FigureS is a sectional view taken along lines 8--8 of Figure '7,

Figure 9 is a top plan view of a plunger' and roller carriage assembly.

According to one example, as shown in Figures 1 to 5, the pressure member for cylinder block Ill of the pump is journaled at HB2 upon a shaft |03 and formed as a hollow cylinder, within which an adjustable double eccentric member Imi/|05, and also the devices for transmitting the forces between the plunger and the eccentric member, are located. A plunger It@ is slidable in the cylinder It?, which extends, like the remaining cylinders, to the outside of the cylinder block I|, and is closed there by means of a closing screw plug |08. The plunger |06 has a cross-head |00, Figures 2 to fi, which is rigidly connected to a similar cross-head of the diametrically opposite plunger H0 by means of two rings III, Figure 2, so that the plungers and iI are kept Yparallel to each other. Within the cross-head m9 there is a yielding member constructed as a rocker IIll, which is movable by means of a cylindrical face upon the cross-head |09. Its straight line contacting with the cross head |09 is perpendicular to the axis of the plunger, for example ||0 and parallel to the axis of shaft |03. A roller carriage I i5 is arranged at the sides of the rocker and guided perpendicularly to the guideways or 'tracks H8 in slots or out outs Il? provided in the cross-head it. These guideways are located on rings H8 and |20, which are rigidly connected with the cylinder block |0I on both sides of the plungers IE5 and IIU. A further pair of plungers with crossheads I3I is arranged at right angles to the pair of plungers |06, H0, and connected together by means of rings |32 in a similar manner to the cross-heads |09. They also carry a rocker IUI, with a roller carriage I IS. The latter, as shown in section on the line (Figure e) has some clearance, so that it is able to transmit freely the tangential pressure from the rocker H0 to the guideway or track |I8. In order to reduce the friction there are rollers |22 on the pin I2i of the carriage, which bears only with its two ends against the rocker IM by means of supporting surfaces |23. The rocker IIII is provided with a semi-circular recess |24, in which sliding shoes |25 shaped correspondingly are swingably journaled. The end I2l of the sliding shoes advancing in case of rotation is formed somewhat longer than the end |28, so as to facilitate the admission of oil below the sliding shoe. The plungers, for example |06 and lit, are screwed into the cross-head |69 by means of a threaded pin |29, and are fitted with a slot 330 for inserting a screw-driver. The cross-heads ISI of the second pair of plungers are rigidly connected together through other rings 32, being adapted symmetrically to that plane which is drawn on a level with the axes of all the plungers. The distance of the rings |32 from this star middle plane is smaller than the distance of the rings III of the pair of plungers Iii-'5, IIi from the same plane. Both the rings |32 are split at H2 (also the rings III) and at the opposite side, whilst they are connected with each other by means of laps through bolts IIS. In order to control the plungers, bores |33 are provided within the cylinder block IOI, these bores communieating with two half-annular grooves itil and |35 in the shaft |03. Supply and discharge will be effected through radial bores E36 and axial channels |37.

During operation the shaft It, which carries the adjustable double eccentric member It, |05, is stationary, whilst the cylinder block IQI rotates. Owing to the pressure between the eccentric member and the plunger there will be created a tangential component from the rocker |I4 through the roller carriage IIG to the guideways IIS, the carriers of which, i. e. the rings IIS, |29, are rigidly connected with 'the cylinder block receiving the cylinders.

According to the second example of embodiment, shown in Figures 6 9, the resilient member, being constructed likewise as a rocker, is journaled in a roller carriage, which is supported in a multiple manner by means of rollers or sliding members, namely: primarily against the eccentric member, for transmitting the pressure of the plunger, secondarily against lateral guideways for transmitting the tangential forces, which might exert a lateral pressure upon the plungers, Vand thirdly against freely running rings, for transmitting the centrifugal forces of the plungers.V By this manner a complete balancing of the plungers from lateral forces will be obtained, besides other advantages.

1Ihe numeral 20| designates the cylinder block, in which four cylinders 202 are located, the supply and discharge of which takes place through channels 203 communicating with annular grooves 204, 205 in the shaft 206 and connecting with'supply and discharge channels 201 through bores 208 andr209. The block 20| rotates upon the shaft 206 carrying a double eccentric member 2 |0/ 2| which may be adjusted in a manner not illustrated. Within the cylinders 202 travel plungers 2| 2, tted with cross-heads 2|3. The

latterA are provided with' round-shaped:` supporting surfaces .2 Hl;` bearing against flatr supporting` faces' 228 ona box-shaped carriage: 2li. Upon an axle2=l 6 ofthiscarriagethere are wheelsl2l'1, which are able to-comeinto contact with guideways` 2I8" and 2l9; The' diameter of the wheels 2|1 is less by about als; mm.` than the distance between the guideways or tracks2:|`8 and 2|9. Furthermore the carriage 215 carries upon its axle 2|6 an oscillating frame 220, which'is-provided with four pairs' of` rollers-122|, bearing` The boxagainst two freely runningrrings 222; shaped` carriage-2li; receivesJ a yielding member constructed as. a .rocker 223i This: yielding member bears by means of a round-shaped: supporting surface 2241 against a flat face of.V the cross-head 213'. Contact takes `pl'ajceLin astraight line which is approximately perpendicular to theplunger axis. The :rocker 223: is movable in a` tangential direction to 'a .smallextent within thebox-shaped carriage `2|5; It receives within a correspondingly cylindricalrecess.aJ cylindrical extension 225r of a roller carrierV `22i5, the rollers of which travel upon the eccentric member 21|, whereby there may. be arranged between the rollers 221 and the eccentric'memberV 2|.I a ring, not shown in the drawing, which is turnable uponthe eccentric memberi2||.. The oscillating axle of the roller carrier 226 coincides approximately with the axle 21B of; thecarria'ge 2|5, so that the axles of the wheels .2|11, the oscillating axleof the frame 220 and the oscillating axle of the roller carrier 226 coincide approximately. The effect thereupon is that all forcesiintersect at a point or on an axis, so that theypartlyl compensate each other, and no lateralA forces can be exerted uponthe plungers 212'.

Instead of the oscillating frame. 220 with the rollers 22 I, two wheels oflarger diameter maybe provided, the` axis' of which` coincides with the axis of the wheels 211, each of them running upon one of the rings 222.

It is therefore clear thatthisinvention provides a hydraulicmachine which isA capable of operating asia pumpor a motor. 'Ihe machine as illustrated in the two embodiments essentially comprises a cylinder block or 20|.. The shaft is within-.the cylinderblock as illustrated at |03 and 206` and the shaft axis constitutes the axis of rotation of the machine. The illustrated cylinder blocks have radially arranged cylinder bores therein loc'at'ed` radially outward of the shaft, someof which are shown-at` |01 and 202 in the respective modifications. Plungers are slideably mounted within the cylinders and eccentric means 104 and |05 in the first form of the invention and 2|0, 2 I in the second form are mounted within the cylinder ,block for cooperation with the plungers; swingable members respectively denoted at |25 and 226 in the two forms. of the invention are" interposedv between each plunger and the eccentric means and these members are swingable about axes parallel to the axis of the shaft. Yieldable members denoted at H4 and 223 are positioned between each plunger and its associated swingable member. 'Ihese yieldable members are yieldable or loosely movable in the direction transverse of each cylinder axis that is at right angles to the shaft axis. Roller means constituted by the roller carriage ||6 in one form and the carriage 220 in the other form are operably associated with each plunger and influenced by movement of each yieldable member in the direction perpendicular to the plunger axis and transverse of the shaft axis. Guide tracks are'` embodied Within the cylinder blocks of each form of theinvention and cooperable with theiroller .meansfor. guiding the same. The guide tracksare disposed in planes parallel to the axisipassing through each cylinder and longitudinal to th'eshaftl axis. By! the arrangement described, the` force betweenthe eccentric means and `plunger istran'smitted-by and through the cooperation of.. the swingable members and the yieldable members. Each yieldable member hasl an arcuate. face engaging its associated plunger in the form of `Figures 1A to 5 so that the contact between the yieldable member and the associated` plunger lies ona straight line extending perpendicular tothe plunger axis and parallel to4 the shaft'axis.'

I claim:

1. A hydraulic machine capable ofv operating as a pump or motor comprising a cylinder block, a shaft therewithin, the axis ofwhichconstitutes the axis of rotation ofthe machine,.said cylinder block having radially arranged cylinder bores therein radially outward of the shaft,` plungers slidably mounted within the cylindersg. eccentric means within the cylinder block for cooperation with the plungers, swingable members .swingable about axes parallel to the shaft axisand respectively interposed between each plunger and the eccentric means, yieldable members yieldableY in the direction transverse of eachVV cylinder axis that is at right angles to the shaft axis; andrespcctively positioned between each plunger and its associated swingable. member, roller means operatively `.associated with each plunger and inrluenced by movementv of. each yieldable member in the direction perpendicular tothe plunger axis and transverse of the shaftaxisguide .tracks embodied within the cylinder block and cooperable with the roller means for guiding the same, said guide tracks being disposed in planes` parallel to planes passing through the axis of` eachcylinder and longitudinally through' the shaft axis and the force betweenthe eccentric means and plunger being transmittedby andk through` the cooperation of the swingable members and the yieldable members.

2. In a hydraulic machine-asvdenedl in and by claim 1, wherein each yieldable member constitutes a cradle and means supporting the cradle for swinging movement in at least one plane perpendicular to the shaft axis.

3. A hydraulic machine according to claim l, wherein each yieldable member has an` arcuate face engaging its associated plunger soy that the contact between the yieldable member and associated plunger lies on a straight line extending approximately perpendicular to the plunger axis and parallel to the shaftaxis.

4. A hydraulic machine as defined in and by claim 1, in which thev roller means includes a roller carriage operatively associated. with each plunger, said guide tracks including two guide tracks for each carriage and eachroller carriage being arranged with slight clearance relative to its pair of guide tracks in thedirection `perpendicular to the plunger axis.

5. A hydraulic machine as defined in and by claim 1, wherein the roller means constitute roller carriages, each plunger having a cross head thereon extending at least in the direction of the shaft axis and means operatively coupling each carriage with a cross head.

6. A hydraulic machine as defined in and by claim 1, wherein each swingable member constitutes a sliding shoe cooperable with the eccentric 7 means, each shoe having an arcuate bearing surface radially spaced from the eccentric means and engaging the rst mentioned bearing surface so that each yieldable member is swingable about an axis parallel to the shaft axis.

7. A hydraulic machine as defined in and by claim l, wherein the plungers are arranged in pairs of opposing plungers and at least one ring rigidly connecting two opposing plungers.

8. A hydraulic machine as defined in and by claim l, wherein the plungers are arranged as pairs of opposing plungers, a pair of rings rigidly connecting each pair of opposing plungers, both rings of the pair of rings connecting each pair of opposing plungers being arranged symmetrical to the plane containing the axesk of all the plungers, one ring of each pair of rings lying in a plane being spaced longitudinally from one side of the plane containing the plunger axes and the other ring of each pair of rings lying in a plane spaced longitudinally from and on the opposite side of the plane containing the plunger axes.

9. A hydraulic machine as defined in and by claim 1, in which a cross Yhead is provided on each plunger, a pair of longitudinally spaced freely running rings Within the cylinder block, the roller means including a roller carriage operatively associated with each plunger, at least one roller carried thereby for cooperation with the guide tracks and additional rollers carried by each carriage and bearing against the rings, each cross head contacting a yieldable member and the respective cooperating contacting surfaces defining a line contact between each cross head and each yieldable member with the line contact extending approximately perpendicular to the axis of the associated plunger and parallel to the shaft axis.

10. A hydraulic machine as defined in and by claim 1, in which a cross head is provided on each plunger, a pair of longitudinally spaced freely running rings within the cylinder block, the roller means including a roller carriage operatively associated with each plunger, at least one roller carried thereby for cooperation with the guide tracks and additional rollers carried by each carriage and bearing against the rings.

11. A hydraulic machine as defined in and by claim l, in which a cross head is provided on each plunger, a pair of longitudinally spaced freely running rings within the cylinder block, the roller means including a roller carriage operatively associated with each plunger, at least one roller carried thereby for cooperation with the guide tracks and additional rollers carried by each carriage and bearing against the rings, and each swingable member constituting a member movably engaging the eccentric means having a head thereon engaging an associated yieldable member, said head having an arcuate surface and each yieldable member having an arcuate socket to receive the head of its associated swingable member so that relative swinging movement between each yieldable member and its associated swingable member is facilitated.

12. A hydraulic machine as dened in and by claim 1, in which the guide tracks constitute spaced tracks extending parallel to and on opposite sides of each plunger axis, the roller means constituting a roller carriage operatively associated With each plunger including at least one roller for cooperative engagement with the guide tracks, a pair, of longitudinally spaced freely running rings within the cylinder block, additional roller means on each roller carriage bearing against the freely running rings, and the axis of each roller means that engages the guide tracks being approximately coaxial with the respective axes about which the swingable members swing.

13. A hydraulic machine as defined in and by claim 1, including two freely running,A rings within the cylinder block, said roller means including a roller carriage operatively associated with each plunger, rollers carried by the carriage in cooperation with the guide track,V a frame swingable about the axis of the last mentioned rollers and carrying additional rollers for cooperation with and bearing against the freely running rings, the swinging axis of each said frame coinciding approximately with the axis of swing of the swingable members which transmit force from the yieldable members to the eccentric means.

1li. A hydraulic machine as defined in and by claim l, and including two freely rotatable rings Within the cylinder block, the roller means including a roller carriage operatively associated with each plunger, and each carrying at least one roller cooperating with the guide tracks, a swingable frame associated with each roller carriage for swinging movement about the axis of the roller that cooperates with the guide tracks, said frame carrying rollers thereon bearing against the freely running rings, the swingable member and yieldable member associated bem tween each plunger and the eccentric means including arcuate engaging surfaces providing an axis about which tne yieldable member and y swingable member can move relative to one another, and the axis of each frame of the rollers engaging the guide tracks, and the axis about which the respective yieldable members and the swingable members move relatively to one another approximately coinciding.

References Cited in the le of this patent UNETED STATES PATENTS Number Name Date 2,138,018 Benedek Nov. 29, 1938 2,160,352 Benedek May 30, 1939 2,173,432 Benedek Sept. 19, 1939 2,217,796 Dell Oct. 15, 1940 2,293,692 Wylie Aug. 18, 1942 2,419,059 De Villiers Apr. 15, 194'! 2,523,543 Smith Sept. 26, 1950 

